Mixpanel MCP Server

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries full burden and adds valuable behavioral context: it specifies the return format (NDJSON), that it returns 'all properties' per event, and the hard cap ('Capped at 5000 events'). However, it doesn't mention pagination, rate limits, authentication needs, or what happens when the cap is reached.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two concise sentences with zero waste: first sentence states purpose and format, second adds critical behavioral constraints (cap). Every word earns its place, and key information is front-loaded.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a data export tool with 5 parameters, 100% schema coverage, and no output schema, the description is reasonably complete: it covers purpose, format, and a key constraint (cap). However, it lacks details on error handling, response structure, or performance implications that would help an agent use it effectively.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so parameters are fully documented in the schema. The description doesn't add any parameter-specific semantics beyond what's in the schema (e.g., it doesn't explain filtering logic or date format nuances). Baseline 3 is appropriate since the schema does the heavy lifting.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the specific action ('Export raw event data as NDJSON'), the resource ('event data'), and distinguishes from siblings by specifying it returns 'individual events with all properties' (unlike aggregated reports or filtered queries). It explicitly mentions the format (NDJSON) and output scope.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage for retrieving raw event data with date ranges and filtering, but doesn't explicitly state when to use this vs. alternatives like 'query_events' or 'top_events'. No guidance on prerequisites, exclusions, or comparative contexts with sibling tools is provided.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.